Conventionally, substrate-integrated waveguides (“SIWs”) are formed by laser drilling holes in a dielectric substrate, including a printed circuit board, down to a lower metal layer. Such holes are filled with a metal to form metal posts, and an upper metal layer is formed over upper ends of such metal posts and on a presently exposed upper surface of such dielectric substrate to form an SIW. However, metal post-to-metal post spacing or pitch is limited to laser drilling spacings, which conventionally such pitch is at a minimum 350 microns. Photolithographic semiconductor processing may be used to form such metal posts with sub-350 micron pitches; however, photolithographic semiconductor processing is substantially more costly than laser drilling.